#include <bits/stdc++.h>
#define CHECK cout << "ok" << endl
#define finish(x) return cout << x << endl, 0
typedef long long ll;
typedef long double ldb;
const int md = 1e9 + 7;
const ll inf = 1e18;
const int OO = 1;
const int OOO = 1;
using namespace std;
struct func {
ll cost, st, en;
func() {
cost = st = en = 0;
}
func(ll c, ll s, ll e) {
cost = c;
st = s;
en = e;
}
ll operator ()(ll x) const {
if (x < st) return cost + st - x;
if (en < x) return cost + x - en;
return cost;
}
};
func merge(const vector<func> &f) {
vector<ll> pos;
for (const auto &i : f) pos.push_back(i.st), pos.push_back(i.en);
sort(pos.begin(), pos.end());
ll st = pos[pos.size() / 2 - 1], en = pos[pos.size() / 2], cost = 0;
for (const auto &i : f)
cost += i(st);
return func(cost, st, en);
}
struct edge {
int to, w;
edge() {}
edge(int tt, int ww) {
to = tt;
w = ww;
}
};
int n;
vector<vector<edge>> g;
func dfs(int v = 0, int prev = -1) {
vector<func> f;
for (const auto &i : g[v])
if (i.to != prev) {
f.push_back(dfs(i.to, v));
f.back().st += i.w;
f.back().en += i.w;
}
if (!f.size()) return func();
return merge(f);
}
int main() {
ios::sync_with_stdio(0), cin.tie(0);
int useless;
cin >> n >> useless;
n += useless;
g.resize(n);
for (int i = 1, p, w; i < n; i++) {
cin >> p >> w;
--p;
g[p].push_back(edge(i, w));
g[i].push_back(edge(p, w));
}
cout << dfs().cost << '\n';
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
384 KB |
Output is correct |
| 2 |
Correct |
3 ms |
384 KB |
Output is correct |
| 3 |
Correct |
2 ms |
384 KB |
Output is correct |
| 4 |
Correct |
4 ms |
384 KB |
Output is correct |
| 5 |
Correct |
2 ms |
384 KB |
Output is correct |
| 6 |
Correct |
2 ms |
384 KB |
Output is correct |
| 7 |
Correct |
3 ms |
384 KB |
Output is correct |
| 8 |
Correct |
2 ms |
384 KB |
Output is correct |
| 9 |
Correct |
3 ms |
384 KB |
Output is correct |
| 10 |
Correct |
2 ms |
384 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
384 KB |
Output is correct |
| 2 |
Correct |
3 ms |
384 KB |
Output is correct |
| 3 |
Incorrect |
2 ms |
384 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
384 KB |
Output is correct |
| 2 |
Correct |
3 ms |
384 KB |
Output is correct |
| 3 |
Correct |
2 ms |
384 KB |
Output is correct |
| 4 |
Correct |
4 ms |
384 KB |
Output is correct |
| 5 |
Correct |
2 ms |
384 KB |
Output is correct |
| 6 |
Correct |
2 ms |
384 KB |
Output is correct |
| 7 |
Correct |
3 ms |
384 KB |
Output is correct |
| 8 |
Correct |
2 ms |
384 KB |
Output is correct |
| 9 |
Correct |
3 ms |
384 KB |
Output is correct |
| 10 |
Correct |
2 ms |
384 KB |
Output is correct |
| 11 |
Correct |
2 ms |
384 KB |
Output is correct |
| 12 |
Correct |
3 ms |
384 KB |
Output is correct |
| 13 |
Incorrect |
2 ms |
384 KB |
Output isn't correct |
| 14 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
3 ms |
384 KB |
Output is correct |
| 2 |
Correct |
3 ms |
384 KB |
Output is correct |
| 3 |
Correct |
2 ms |
384 KB |
Output is correct |
| 4 |
Correct |
4 ms |
384 KB |
Output is correct |
| 5 |
Correct |
2 ms |
384 KB |
Output is correct |
| 6 |
Correct |
2 ms |
384 KB |
Output is correct |
| 7 |
Correct |
3 ms |
384 KB |
Output is correct |
| 8 |
Correct |
2 ms |
384 KB |
Output is correct |
| 9 |
Correct |
3 ms |
384 KB |
Output is correct |
| 10 |
Correct |
2 ms |
384 KB |
Output is correct |
| 11 |
Correct |
2 ms |
384 KB |
Output is correct |
| 12 |
Correct |
3 ms |
384 KB |
Output is correct |
| 13 |
Incorrect |
2 ms |
384 KB |
Output isn't correct |
| 14 |
Halted |
0 ms |
0 KB |
- |
